Boulders & Basements

            Obtaining acquired structures is a first-rate asset within our fire service.  If an organization is fortunate enough to have a good training division with members actively working with contractors, developers, and the building department of their city; you can’t put a price on it.  Besides the obvious array of training opportunities, (ie:  advancing hand-lines, opening up the roof, reduced profiles, shoring, etc.) they provide us with unique opportunities to explore compartments within the structure oftentimes less explored.  As stated in, Below Grade Access Hazards: Part 1, one compartment we may not have regular access to while running routine medical emergencies is the basement.  A few weeks back while training at our most recent acquired structure, we were presented with a hazard I had not only never seen before, but one I never even imagined existed.

                    (Photos taken by Milford FF Mike Plavcan)

            Describing the structure as a small bungalow built in 1935, coming in just over 1,300 sq feet, as is the case with like structured bungalows; the basement stairs weren’t the easiest locate.  Once locating the stairs and descending into the

(Photo #1)

basement what we found was quite remarkable… a boulder.  There was an actual boulder sitting in the middle of the basement.  I’m not talking about a graded ledge which many times makes up one of the walls/floors, or a small rock that was deliberately placed to weigh down an object, but an actual boulder.  A boulder that was approximately 12 feet in diameter and from certain angles looked to have almost an egg shape to it.  You might ask “Well why would someone place a boulder in the basement?”  I'm by no means a structural engineer, however to the best of my knowledge it was not placed there but instead was always present in some capacity.  The boulder may have orignianly been partialy exposed through the basement wall or completely reseting on the exterior of the wall placing immense pressure upon the foundation.  Over time the pressure of the boulder may have weakened the wall causing the boulder to penetrate further into the basement (photo #2 suggests this as we see rubble from the earth beneath the boulder and newer looking dug fur used to shore up the ceiling).  While under construction, for whatever reason, the

                                                                                                                                                                                     (Photo #2)

builder in 1935 decided that instead of blasting it, removing it, or setting the building further back into the rather “deep lot”, they decided to build the foundation of the house around it. Maybe this is something that is common in other areas of the country?  I’ve scene basements built into ledge, smaller rocks scattered throughout crawl spaces, but never a boulder in a basement.

            So why does this matter? It matters because it could create a serious hazard while performing operations.  These are just a few of the many possible hazards:

1. As shown in (photo #3), the boulder sits directly next to the hot water heater and boiler.  Not shown in the picture is the breaker panel, which also sits in the corner near the other utilities.  To gain access to this corner of utilities there is only a few feet between the wall and the boulder.  If dealing with a fire in either the panel, water heater, or boiler, the boulder would significantly reduce ones profile.

                                ( Photo #3)  The Boulder presents a potential reduced profile situation in order to access utility control.                     

2. If the units were not on fire but instead were tasked with utility control, and conditions were reduced to zero visibility; one may have an extremely difficult time navigating around the boulder. With no visibility, one would be searching for the utilities and most likely assume the boulder was actually a perimeter wall.  Once reaching the end of the boulder, the stairs, which are approximately a foot away, may cause the firefighter assigned to utility control to miss this small opening and continue searching, doubling back down the next perimeter wall.

3. With the boulder being built into or pushed through the foundation, we can stand to reason that if the structural stability were to become compromised even further under fire conditions, the boulder could shift more causing a crush hazard.  Also if the boulder shifted firefighters could become trapped behind it creating a trapped firefighter scenario.

4. If fire conditions weakened the structure enough to cause the boulder to shift even more, it could potentially be a contributing cause for collapse. (Again, not an engineer, but assume this to be a strong possibility.)

            As firefighters, it is our job to be driven to a constant state of vigilance.  When we have the chance to acquire a structure, utilize the opportunity.  Get inside.  Get into the walls and see what the building is made of.  Get into the attic and see what construction techniques were utilized.  Explore the different compartments and see if your presented with something you’ve never scene before.  Walking down the stairs to the basement, I thought I might be surprised by a rat or something along those lines.  Never in a million years did we think we were going to be presented with a boulder that was incorporated as part of the actual foundation. 

Adam J. Hansen